Cockchafer Melolontha melolontha
Sometimes known informally as May Bug. Some moth-trappers call them Blunder Bugs due to their habit of blundering about and crashing into the moths or the observers looking at the moths. They can appear in numbers at moth lights and can then be quite a nuisance for moth trappers - fortunately I don't get too many in my garden moth trap.
They are easy to identify, but I have seen moth trappers get them mixed up with Summer Chafers Amphimallon solstitiale which fly later in the summer (mid June to late July mainly: Cockchafers mostly fly from early May to early June).
Cockchafer Melolontha melolontha, North Elmham (Norfolk, UK), 21st May 2017
Cockchafer Melolontha melolontha, North Elmham (Norfolk, UK), 3rd June 2022
Cockchafer(s?) Melolontha melolontha, Weston Park (Norfolk, UK), 1st June 2013
2x Cockchafers Melolontha melolontha, North Elmham (Norfolk, UK), 28th May 2021
Cockchafer Melolontha melolontha, North Elmham (Norfolk, UK), 2nd June 2022
Cockchafer Melolontha melolontha, North Elmham (Norfolk, UK), 14th May 2018
Cockchafer(s?) Melolontha melolontha, Moorgate Carr (Norfolk, UK), 26th May 2012
Cockchafer Melolontha melolontha, Wendling Beck Environment Project (Norfolk, UK), 7th May 2023
Cockchafer Melolontha melolontha, Creaking Gate Lake, near Bittering (Norfolk, UK), 22nd May 2015
2-3x Cockchafers Melolontha melolontha, North Elmham Cathedral Meadows (Norfolk, UK), 25th May 2019
Cockchafer Melolontha melolontha, North Elmham Cathedral Meadows (Norfolk, UK), 17th May 2020
Cockchafer Melolontha melolontha, North Elmham Cathedral Meadows (Norfolk, UK), 2nd June 2021
Cockchafer Melolontha melolontha, Bawdeswell (Norfolk, UK), 31st May 2010